Of the three atoll reefs off the coast of Belize, Lighthouse Reef is the farthest offshore and home to one of the most popular dive sites in the Caribbean, the Great Blue Hole made famous in the mid 1970s by Jacques Cousteau's Calypso Expeditions.

There are six cayes in the atoll. In the north, Sandbore Caye is one of the two cayes equipped with lighthouses occupied by a keeper and his family. Nearby is Northern Caye and these two cayes are known locally as Northern Two Cayes. On Northern Caye is one of the newest offshore diving resorts. Much of the caye has well-matured mangroves and there is an internal lagoon. The caye is noted for its saltwater crocodiles and snowy egrets.

The most popular caye at Lighthouse Reef atoll is Half-moon Caye located at the southeast corner. Half-moon Caye is divided into two very distinct ecosystems. The western half of the caye is densely vegetated. The soils are made rich and fertile by guano from thousands of sea birds nesting in the area. The eastern half by comparison is vegetated primarily by coconut palms and very little underbrush.

One of the principle inhabitants of Half Moon Caye's western side is the Red-footed Booby, numbering around 4000 breeding birds. This area was the first reserve to be established by the Natural Parks System Act of 1981 in Belize. The adult booby population found on the island is unusual in having an almost total predominance of the white color phase. The only other similar booby colony is on an island near Tobago. Elsewhere, adult Red-footed Boobies are dull brown.

Half Moon Caye Natural Monument, encompasses 10,000 acres of the atoll and 15 square miles of surrounding waters. Beyond the drop off at the south end of the caye the water depth increases to over 2000 feet. Here, the deep water species lurk-huge jewfish over 5 feet long; the ferocious and harmful baracuda can reach sizes of 5 or six feet. Blue marlin prowl the deeps off Lighthouse Reef, searching for the schools of jacks and dolphins (the fish, not the mammal) for food. Half Moon Caye and Lighthouse Reef are truly one of the marine gems of not only Belize, but of the world. And as if all this is not enough, to the north of Half Moon Caye, lies the famous Blue Hole. "Half Moon Caye Natural Monument was designated as a World Heritage Site in 1996."

If you're an experienced nature-watcher you'll see many different kinds of birds and iguanas (locally called Wish Willies) and all sorts of strange minor wildlife

Apart from the boobies, some 98 other species of birds have been recorded on the caye, including warblers, ospreys and white-crowned pigeons and the magnificent frigate bird. The caye has a lighthouse and excellent beaches, as well as a submerged wall just offshore that is teeming with marine flora and fauna.